1// Copyright 2014 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef COMPONENTS_METRICS_SERIALIZATION_SERIALIZATION_UTILS_H_
6#define COMPONENTS_METRICS_SERIALIZATION_SERIALIZATION_UTILS_H_
7
8#include <string>
9
10#include "base/memory/scoped_ptr.h"
11#include "base/memory/scoped_vector.h"
12
13namespace metrics {
14
15class MetricSample;
16
17// Metrics helpers to serialize and deserialize metrics collected by
18// ChromeOS.
19namespace SerializationUtils {
20
21// Deserializes a sample passed as a string and return a sample.
22// The return value will either be a scoped_ptr to a Metric sample (if the
23// deserialization was successful) or a NULL scoped_ptr.
24scoped_ptr<MetricSample> ParseSample(const std::string& sample);
25
26// Reads all samples from a file and truncate the file when done.
27void ReadAndTruncateMetricsFromFile(const std::string& filename,
28                                    ScopedVector<MetricSample>* metrics);
29
30// Serializes a sample and write it to filename.
31// The format for the message is:
32//  message_size, serialized_message
33// where
34//  * message_size is the total length of the message (message_size +
35//    serialized_message) on 4 bytes
36//  * serialized_message is the serialized version of sample (using ToString)
37//
38//  NB: the file will never leave the device so message_size will be written
39//  with the architecture's endianness.
40bool WriteMetricToFile(const MetricSample& sample, const std::string& filename);
41
42// Maximum length of a serialized message
43static const int kMessageMaxLength = 1024;
44
45}  // namespace SerializationUtils
46}  // namespace metrics
47
48#endif  // COMPONENTS_METRICS_SERIALIZATION_SERIALIZATION_UTILS_H_
49